1. Field Of The Invention
The field of art to which this invention pertains includes cams and cam followers, particularly double oscillating motion - single linear motion cams, that find utility, for example, in shift control systems for power transmissions having multiple input and output portions.
2. Description Of The Prior Art
My prior U.S. Pat. No. 4,000,662, which issued on Jan. 4, 1977 and is also assigned to the present assignee, discloses a highly advantageous form of transmission having a basic structure which provides axially aligned input and output shafts together with a single aligned countershaft as well as first, second and third input gears and a plurality of forward output gears, with one of the forward output gears also being capable of serving as one of the input gears. First, second and third driven countershaft gears are in constant mesh with respective ones of the input gears and each one of a plurality of driving countershaft gears is in constant mesh with a separate one of the forward output gears, with one of the driving countershaft gears also being capable of serving as one of the driven countershaft gears. Multiple clutch means are utilized for selectively drivably connecting the countershaft with one of the input gears and for selectively drivably connecting the output shaft with the countershaft.
The multiple use of some of the gears of this transmission together with the triple input feature and the single countershaft permit utilization of a transmission housing that has but two through bores, and in one embodiment, all of the components for a nine speed forward and three speed reverse transmission can be located completely within a standard five speed forward--one speed reverse transmission housing.
My co-pending application Ser. No. 731,391, filed Oct. 12, 1976, now U.S. Pat. No. 4,068,537, issued Jan. 17, 1978, which again is assigned to the present assignee, discloses a sophisticated shift control system of the preselector or semi-automatic type wherein shifts between drive ratios are made in response to the movement of an operator's shift lever and the release of the torque on the drive train.
In order to both reduce the complexity and cost of the aforesaid shift control system, I have made an invention entitled "Manual Shift Control System For A Multiple Input - Multiple Output Transmission" in which the present invention takes the form of a one-way cam that can be actuated bidirectionally yet always moves a transmission shift rail in one and the same direction.
Prior art transmission control systems that utilize cams include U.S. Pat. Nos. 1,118,389; 1,928,782; 3,487,713; 3,429,194; 3,431,791; and 3,857,299.